Marquee Requires No PLC Reprogramming

Uticor's PowerMarquee Family

Jun 16, 2003

Conventional marquees interact with the process PLC program, so adding a marquee means modifying the control program. New PowerMarquee displays from Uticor eliminate the need for PLC reprogramming. Shalli Kumar, Uticor chairman and CEO, says, "Applying a marquee could not be simpler."

Most marquees currently available fall into one of two categories. The first group simply displays a message sent to the marquees by a controller. The controller forms the message along with its attributes (character sizes, scroll, etc.), and sends it to one or more marquees in the network. These marquees, often called slave marquees, do not store any messages. The controller stores all the messages, decides which messages must be displayed, and sends formatted messages at appropriate times to the marquees. Kumar says, "Adding such a marquee to an existing control system requires extensive modifications to the controller program."

The second group, often called master marquees, stores a database of messages and displays them under the direction of a controller. The controller still decides which messages must be displayed on the marquee, and communicates a message number through a message-number register. The marquee looks up the message number in its message database and displays the message. "The controller in this case is not burdened with storing and formatting messages," Kumar says, "but it still needs to decide which message to display." Adding a master marquee still requires modifications to controller program.

The new PowerMarquees store the messages as well as the conditions for when the messages must be displayed. They monitor various controller registers, solve for the conditions, and display those messages for which the conditions of display are satisfied. "The new marquees do not burden the controller, and can be added to a control network without modification to control program," Kumar says.

PowerMarquees offer connectivity to most of the popular PLC networks (including Allen-Bradley, Modicon, GE, and Siemens). "And like other marquees from Uticor, they use matched LEDs so the LEDs age similarly and provide uniform brightness throughout the life of marquee," Kumar says. "The company subjects PowerMarquees to a 96-hour burn-in. Combined with a reliable, time-proven design, this allows Uticor to offer a four-year warranty on its marquee products."

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